Ventricular fibrillation is a life-threatening medical condition in which the electrical activity of a person's heart becomes unsynchronized, resulting in a loss of ability of the heart to pump blood into the person's circulation system. Ventricular fibrillation may be treated by applying one or more strong electrical pulses to the person's heart which gives it a chance to reinitiate a synchronized rhythm. The electrical pulse must be delivered within a short time after onset of ventricular fibrillation for the person to have a reasonable chance of survival.
Automated external defibrillators (AEDs) are typically used by first responders, such as police officers, firefighters and EMTs, to resuscitate victims of ventricular fibrillation or other shockable cardiac arrhythmias. AEDs tend to be more lightweight, compact and portable than manual defibrillators. Because first responders typically have less extensive medical training, AEDs are designed with a simple user interface. After attaching the AED electrode pads to the patient, the user instructs the AED to analyze the patient's condition. If the patient is found to have a shockable cardiac rhythm, the user is advised to stand clear while the AED delivers a defibrillation pulse to the patient.
At present, AEDs are designed to treat adult patients and are not recommended for pediatric patients. Present therapy protocols issued by the American Heart Association for AEDs recommend usage on patients of age eight and above. Nevertheless, cardiac arrest can occur in patients less than eight years old. There is, therefore, a desire for AEDs to be capable of treating pediatric patients.
Pediatric patients generally require lower energy levels for defibrillation than adult patients. For an AED to provide reduced defibrillation energies to pediatric patients, the AED must recognize when it is attached to a pediatric patient. Some prior art approaches have suggested providing the user with multiple sets of electrodes designed for use with different patients of different ages or weights. The electrode sets provide an electrical or mechanical indication to the AED that identifies which electrode set has been connected to the AED. However, providing multiple electrode sets of this type increases the overall cost of the AED.
Other approaches in the prior art have suggested providing an energy reduction apparatus that is connected between the AED and the pediatric patient. An AED of this type delivers a defibrillation pulse of adult dosage. For a pediatric patient, however, the energy reduction apparatus reduces the delivered energy to a level presumably appropriate for the pediatric patient. Connecting an energy reduction apparatus as suggested in the prior art requires additional consideration and effort by the user which may delay treatment. It also adds to the complexity and cost of the AED, and is energy inefficient.
Accordingly, there is a need for an AED that can automatically determine whether it is attached to an adult or pediatric patient based on information entered by the user in the course of AED operation. A need further exists for an AED that adjusts its operational aspects, such as energy delivery, for pediatric patients based on the user-entered information.